Re: Getting keyboard state.

["Timothy M. Shead" <tshead k-3d com>]

Philip Kendall wrote:

> On Sat, Jan 13, 2001 at 04:43:26PM +0700, Maxim Koshelev wrote:
>
> > Havoc Pennington wrote:
> >
> > > Maintaining the state is much more correct, the get_pointer() solution
> > > is a giant race condition.
> >
> > Race conditions must be checked only in multithreaded programs where more
> > than one thread work with gtk...
>
>
> NO! See Havoc's previous post...
>
> Consider the following situation:
>
> * Key pressed, without shift. Event generated and sent to X server.
> * [... time passes whilst your GTK program does complicated processing]
> * User finishes pressing key. [...time passes...]. User presses shift.
> * [... time passes ... ]
> * GTK+ program now reads key event, which was a key being pressed
>   _without_ shift. You call get_pointer(...) and get shift being
>   pressed. WRONG ANSWER!

Disclaimer:

I probably should've made it clear that keyboard and mouse events 
already contain information about modifiers, so if you're handling those 
events you don't need to resort to the get_pointer() trick.  It was 
presented as a solution to the original question as I interpreted it: 
"how do I get the state of the keyboard *right now*" i.e. not in 
response to an event.  Odds are, you'll never need to do this.

Cheerio,
Tim